Slush nozzle for drill bits



April 14, 1953 2 SHEETS-SHEET 1 Filed Dec. 13, 1948 m NM W kT H y. wf yM w m GIMME 6 "M M M d d H Y r 5 m y p A T TORNEYJ Ap 1953 J. c. STOKES2,634,953

SLUSH NOZZLE FOR DRILL BITS Filed Dec. 13, 1948 2 SHEETS-SHEET 2JNI/ENTOR CLMA A r TORNEYJ Patented Apr. 14, 1953 SLUSH NOZZLE FOR DRILLBITS John C. Stokes, Houston, Tex., assignor to Reed Roller Bit Company,Houston, Tex., a corporation of Texas Application December 13, 1948,Serial No. 64,926

This invention relates to new and useful improvements in slush nozzlesfor drill bits and relates particularly to means for mounting saidnozzles.

In the drilling of wells, a mud laden fluid generally known as slush ordrilling mud is pumped downwardly through the drill stem and is directedoutwardly through slush openings in the drill bit at the lower end ofthe drill stem, returning to the surface of the earth through theannular space between the drill stem and Well bore. The slush ordrilling fluid is circulated at relatively high pressures and velocitiesand is extremely abrasive, with the result that the bore of the slushopenings in the bit body are subjected to wear. In order to preventabrasion and cutting out of the walls of the slush openings, it hasbecome the practice to mount abrasion-resistant nozzles in saidopenings. Because of the excessive abrasive action of the circulatingfluid, it is preferable that the slush nozzle or tube be constructed ofa material which is particularly resistant to such abrasion so thatextended use with minimum deformation of the nozzle bore may beobtained; however, because the nozzle will eventually become worn andrequire replacement, it is also desirable that the nozzle be mounted foreasy replacement within the slush opening of the bit.

Probably the best known material having maximum abrasion-resistantqualities is tungstencarbide, and this material has been foundsatisfactory for the construction of slush nozzles. Buttungsten-carbide, becaus of its extreme hardness, cannot be accuratelyshaped or worked after forming, either by grinding or cutting andtherefore, a slush nozzle constructed of tungstencarbide does not lenditself to removable mounting within a drill bit body.

It is, therefore, one object of the present invention to provide animproved slush nozzle which has the Wall of its bore, through which thedrilling fluid is circulated, constructed of an abrasionresistantmaterial and which may be removably mounted with a drill bit bodywhereby replacement of the nozzle is facilitated.

An important object of the invention is to provide an improved slushnozzle whereinthe slush tube proper is constructed of anabrasion-resistant material andis bonded to an outer bushing by weldingor brazing, with the latter being formed with screw-threads whereby theunit may be readily mounted in and removed from a threaded opening inthe drill bit body; the use of threads for making the connectionpermitting mounting and removal of the nozzle unit in the 1 Claim. (Cl.255-431) field and without the use of any special tools or equipment.

Another object is to provide an improved slush nozzle unit comprising atubular abrasion-resistant tube which is welded within the bore of amounting bushing, with the latter having external threads which arepreferably formed on a taper similar to standard pipe threads, whereby aleakproof connection between the bushing and bit body is assured and theuse of special packing or seals is not required.

Still another object of the invention is to provide an improved slushnozzle unit which is particularly adaptable for mounting in a blade-typebit and which is constructed so that it may be mounted in said biteither from the exterior or the interior of said bit body.

The construction designed to carry out the invention will be hereinafterdescribed together with other features of the invention.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawings,wherein an example of the invention i shown, and wherein:

Figure 1 is a transverse, sectional view of a blade-type bit having aslush nozzle unit, constructed in accordance with the invention, mountedtherein.

Figure 2 is a view, partly in section and partly in elevation of theslush nozzle,

Figure 3 is a plan view thereof,

Figure 4 is a view, similar to Figure 1, and illustrating a slightlymodified form of the invention,

Figure 5 is a view, partly in section and partly in elevation of theform of nozzle shown in Figure 4, and

Figure 6 is a plan view of the nozzle shown in Figure 5.

In the drawings, the numeral Hi designates the body of a drill bithaving radially disposed cutting blades I I at its lower end. The upperend of the bore ll of the bit body i formed with the usual screwthreads, whereby the bit may be coupled to the lower end of a drill stem(not shown) in the usual manner. An inclined fluid circulating or slushopening I2 is formed in the lower portion ofthe bit body l0 and isdisposed adjacent each bit blade I I, whereby drilling fluid circulateddownwardly through the opening is directed into contact with the surfaceof the blade to wash the same during the drilling operation. The wall ofeach opening I2 is formed with screw threads [3.

The improved slush nozzle unit A is adapted to be mounted within eachslush opening I2 and includes an outer bushing l4 provided with externalthreads [5. The bushing has an axial bore l6 extending entirelytherethrough and one end of said bushing has its external surface formedwith suitable wrench flats H. A slush tube or nozzle l8 which isconstructed of tungsten-carbide or other suitable abrasion-resistantmaterial is insertable within the bushing 14 and extends substantiallythroughout the length thereof. It is preferable that one end of the tube18 project a slight distance beyond the end of the bushing whereby anannular bead of welding material :9 may secure the tube to the bushing.It is pointed out that since the tube [8 is constructed oftungsten-carbide or other abrasion-resistant material, the material ofsaid tube does not lend itself to shaping after it is once formed and itwould be substantially impossible to provide threads on the externalsurface of the tube 13. Thus, the tube actually forms anabrasion-resistant liner or sleeve within the bore of the bushing andobviously, when the bushing is in place within the slush opening [2, thecirculating fluid or slush flows downwardly through the slush tube.Since the tube is constructed of a hard, long wearing material, cuttingout and excessive Wear of the nozzle is minimized.

It is preferable that the threads 15 on the bushing and the internalthreads 13 within each slush opening 12 be formed on a taper, similar tothe usual pipe threads, so that when the bushing is mounted within theopening, a fluidtight seal is produced. It is also preferable that thewrench flats ll be provided at the upper end of the unit so that theslush nozzle unit may be mounted within the opening from the interior ofthe bit body. This may be accomplished by engaging any suitable socketwrench with the wrench flats, said wrench operating through the bore IIfrom the upper end of the bit body. When replacement of the unit A isnecessary, this may be readily accomplished in the field since nospecial tools or equipment are required. The arrangement makes itpossible to employ the abrasion-resistant material for lining the slushopening l2 and yet make the nozzle readily replaceable when desired. Ashas been noted, the tungsten-carbide o r abrasion-resistant tube I8extends substantially throughout the length of the bore 16 of thebushing, and as illustrated, one end of said tube terminates short ofthe lower end of the bushing to accommodate an annular weld 20. It ispreferable that the welds 20 be within the lower portion of the bore ofthe bushing rather than at the extremity of the bushing because of thethreads l which are formed on the exterior of the bushing and whichmight be subject to damage by a welding operation. 7

It is not necessary that the nozzle unit be mounted in position fromwithin the body 10 of the drill bit and in Figures 4-6, a slightlymodified form of the invention is shown. In this form, a nozzle unit Bwhich includes an outer bushing Ma, and an inner slush tube 18a isadapted to be mounted within a slush opening 12a within the bit body IDby introducing the unit from the exterior of said body. The bushing Mahas external screw threads I5a arrangedto engage internal threads 13awithin the opening and the end of the bushing is formed with transverseslots 2| in its lower peripheral portion, whereby a screw driver orwrench having a transverse rib may be engaged therewith to tighten theunit B within the opening. As illustrated, the lower end of the innerslush tube 18a terminates short of the lower end of the bushing and iswelded to the bore thereof by the welding material 29a. The opposite orupper end of the tube I80. is shown as projecting some distance beyondthe upper end of the bushing, being welded to said upper end of thebushing at l9a. It is apparent that this form functions in the samemanner as the first form of the invention and provides a nozzle unitwhich is readily removable from the bit body. While being readilyreplaceable because of the screw threaded mounting, the unit stillprovides an inner lining or tube 18a which may be constructed oftungsten-carbide or other hard abrasion-resistant material. In bothforms of the invention, the threaded bushing which may be easily mountedor removed from the bit body has the inner lining or sleeve formed bythe abrasion-resistant tubes I9 and 18a. In the first form, the unit Ais inserted through the bore H into the bit body and is threaded intothe opening, while in the second form, shown in Figures 4-6, the unit isintroduced into the opening 12 from the exterior of the pin. Althoughthe tubes 18 and 13a have been described as welded to the bushings, itis apparent that brazing or some other suitable bonding means may beemployed for securing these parts together.

The foregoing description of the invention is explanatory thereof andvarious changes in the size, shape and materials, as well as in thedetails of the illustrated construction may be made, within the scope ofthe appended claim, without departing from the spirit of the invention.

Having described the invention, I claim:

A slush nozzle unit for drill bits, including, a tubular bushing havingscrew threads on its external surface, said threads being formed on ataper, an abrasion-resistant slush tube extending within said bushingbut having the lower end of the tube above the lower end of the bushing,a weld between the tube and the bushing at their lower ends with suchweld being disposed inwardly of the bushing threads to avoid damage tosaid threads during welding, and said slush tube being constructed of ahardened metallic material which does not lend itself to machiningoperations.

JOHN C. STOKES.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,639,065 Thagard Aug. 16, 1927 1,754,671 Dahl Apr. 15, 19302,017,834 Hummel Oct. 15, 1935 2,055,144 Christian .1. Sept. 22, 19362,108,955 Zublin Feb. 2 1938 2,118,542 Zublin 1 1 .1 May 24, 19382,119,349 Pearce May 31, 1938 2,141,841 Howard et al. Dec. 27, 19382,221,242 McClelland Nov. 12, 1940 2,290,595 Kinnear July 21, 19422,408,892 Stokes 1 Oct. 8, 1946

